Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Fluid mechanics: Bubble impacts caught on film

When a bubble of air rising through water hits a sheet of glass, it doesn’t simply stop — it squishes, rebounds, and rises again, before slowly moving to the barrier. An international research team with high-speed cameras reveal the complex physics at work as air meets water and glass.
When a bubble of air rising through water hits a sheet of glass, it doesn’t simply stop — it squishes, rebounds, and rises again, before slowly moving to the barrier. This seemingly simple process actually involves some knotty fluid mechanics. An international research team, including researchers at the A*STAR Institute of High Performance Computing, and Nanyang Technological University, Singapore, has now unpicked this physical process.

The researchers used a fine capillary to blow air bubbles 0.5 to 1.5 millimeters wide into a glass of de-ionized water. The bubbles rose 5 millimeters before hitting a glass cover, all under the watchful eye of a high-speed camera. Meanwhile, a laser beam shining from above illuminated the contact points between glass, water and the bubble, created a changing interference pattern that was captured by a second camera running at up to 54,000 frames per second.

A bubble typically took about 17 milliseconds to impact, bounce and return to the glass slide. But a film of water remained between them; it took a further 250 milliseconds for that to drain away before the bubble’s air came into direct contact with the glass. “The film drains slowly because the process is controlled by viscosity and surface tension,” says team member Rogerio Manica. “Eventually, this layer breaks and a three-phase contact line — water, glass and air — forms, with a region on the glass surface that is not wet.” This ‘dewetting’ stage is about 100 times faster than the film drainage process.

The researchers found that a simple mathematical model, called lubrication theory, could accurately describe the film drainage measured in the experiments. “We thus understand the fluid mechanics now in very great detail,” says Manica. “Many industrially relevant processes use impacting bubbles, including wastewater cleaning and mineral extraction,” he says, adding that simulations of these processes can now be improved by incorporating the team’s bubble model.

Other researchers had studied the behavior of much smaller bubbles when rising at very slow speeds. They found that the bubbles settled on to the cover without bouncing, thus skipping the most complex parts of the process.

Manica notes that their experiments also demonstrated the utility of synchronizing cameras to study two very different length scales — the side view is measured in millimeters, while the interferometry camera captures features thousands of times smaller. The researchers are now investigating how rising bubbles behave if the water contains small amounts of other materials, such as surfactants.

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing

Journal information

Hendrix, M. H. W., Manica, R., Klaseboer, E., Chan, D. Y. C. & Ohl, C.-D. Spatiotemporal evolution of thin liquid films during impact of water bubbles on glass on a micrometer to nanometer scale. Physical Review Letters 108, 247803 (2012).

A*STAR Research | Research asia research news
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>